Cylinder grinder



March 13, 1934. M. c. HUTTO L Q CYLINDER GRINDER Filed April 1, 1927 3Sheets-Sheet 1 I INVENTOR. WMDE 6799770 ATTORNEY.

March 13, 19

M. C; HUTTO CYLINDER GRINDER Filed April 1, 1927 3 Sheets-Sheet 2 March13, .1934.

M. c. HUTTO CYLINDER GRINDER Filed April 1, 1927 3 Sheets-Sheet 3 llllll |1 I 0 b rl [III I! A TTORNEY.

Patented Mar. 13,- 1934 UNITED STATES PATENT OFFICE CYLINDER GRINDERMarsden C. Hutto, Detroit, Mich., assignor to Hutto Engineering Company,Inc., a corporation of Michigan- Application April 1, 1927, Serial No.180,159

43 Claims. (01. 51-1843) This invention relates to cylinder grindersFig. 6 is a cross section taken on line 66 of similar in form andoperation to that disclosed Fig. 5. in my Letters Patent of the UnitedStates No. As shown more clearly in Fig. 3 the device conl,610,681,issued December 14, 1926. sists of abody 1 preferably of cylindricalform As is set forth in the said patent the strucand having acylindrical aperture 2 extending 3 ture disclosed therein includes abody and plurallongitudinally thereof. This body has a threadity ofradially adjustable abrading members ined end 3 on which is secured thenut 4 and lock eluding a carrier having fixed pins extending nut 5providing a housing for the driver 6 which through apertures in the bodyto engagement with has a ball end 7 and pins 8, 8 engaging in slotsadjustable cones by means of which the limit of 9, 9 respectively of thesaid end of the body. The 65 contraction of the cones in operation ispositively member 5 is preferably slotted at 10 to permit indeterminedand as set forth in the said patent troduction of the pins to place.However, this the device is made with the usual clearancesparconstruction as to the driver and its mode of ticularly the pins andthe apertures therefor attachment to the body is not of particular im-116 which within limits permits the stones to occupy portance in thisinvention. Any means by which 70 a position at a slight angle to theaxis of the tool the body may be rotated and reciprocated may and thusenables the abrasive members to conbe employed. Preferably, however, thedriving tact the wall of a cylinder that is slightly tapered. meansshould be readily removable or means The principal feature of thisinvention is to provided to permit adjustment of the bolt 12 provide atool of the same general character with whose function is hereinafterdescribed. 5 an improved construction, arrangement and rela- The body isprovided with a series of radial tionship of parts enabling the abrasivemembers bosses 13, 13 of the desired number near one end to assume agreater angle to the longitudinal axis of the device and a similarseries of radial bosses of the tool than is possible with the structure14 adjacent the opposite end. These bosses have shown in the said patentand to secure a greater apertures opening into the central aperture 28-11 freedom of operation of the devices and less liaas will beunderstood from Fig. 3. In these bosses bility to bind due to expansionresulting from the are the pins 15, 15 having plane outer ends and heatevolved in the grinding operation. This tool coned inner ends indicatedat 16. is to be reciprocated and rotated in the cylinder Mounted in thecentral aperture 2 is the conbeing ground and the stones or abrasivememtrol member consisting of cones 17 and 18, the bers are forcibly setinto contact with the wall of cone 17 being threaded for threadedengagement the cylinder with the result that considerable with the rod12 and the cone 18 having an aperfriction and consequent heat isdeveloped tendture for the rod 12 and a recess for the head 11 ing toexpand the parts. of the rod. A coiled spring of barrel shape indi- 35The purpose of this invention is to provide a cated at 19 is positionedbetween the cones 17 and construction which will enable the grinding op-18 for maintaining them in spaced relation. eration to be performedunder greater pressure This control unit consisting of two cones 17 andand therefore with greater rapidity of operation 18, adjusting rod 12,and the spring 19 being movin that the parts are so designed that theexpanable as a unit in the longitudinal aperture 2 and so sionoccasioned by the heat developed does not resubject to control by thepins 15 through the sult in a binding of the parts or restrict theirpressure exerted thereon by the abrasive in concooperative function.tact with the Wall being ground.

These and other objects and novel features of The abrasive members eachconsist of a shell the invention are hereinafter more fully described ofchanneled cross section indicated at 20 and 45 and claimed, and acylinder grinder embodying the stone 21 is secured therein in anyapproved my invention is shown in the preferred form in manner butpreferably after the manner dethe accompanying drawings in whichscribedin my pending application Serial No.

Fig. 1 is a side elevation of one form thereof. 154,280. Whatever themethod and means used Fig. 2 is an end view taken on the line 2-2 of tosecure the stone in its carrier or holder 20, the

50 Fig. l. face of the stone is preferably parallel with the Fig. 3 is alongitudinal section of the device. base of the holder so that uponbeing mounted on Fig. 4 is a cross section of the device taken apthepins 15 as shown in Fig. 3 the face of the stone proximately on line 44of Fig. 3. when the control element is in central position Fig. 5 is alongitudinal section of an alternative lies at a right angle to the axisof the pins 15.

- form of the grinder. As will be observed, the carrier is unattached tothe pins and'each of the pins, as shown in Figs. 3 and 4 terminates in afiat end at a right angle to the pin axis and the carriers merely restupon these pins.

In the operation of the grinder as hereinafter mentioned and due to theforce with which the faces of the abrasives are held in engagement withthe wall being ground considerable torque or side strain is imposed uponthe stone and carrier and to prevent lateral displacement of thecarriers in operation and to take such-torque I have provided slots inthe head of the radial bosses as is indicated at 22 in Fig. 4.

These carriers lie in aligned slots 22 of each pair of bosses 13 and 14and each of the carriers is provided with projecting lugs 23, 23 atopposite ends thereof to receive a coiled garter spring 24 at one endand 25 at the opposite end encircling the group of carriers and tendingto contract the carriers and hold the same in contact with the outerends of the respective pins 15. Inasmuch as these carriers are looselymounted in the slots 22 provided therefor I have provided a means forpreventing longitudinal displacement thereof. For this purpose the sidewalls of the carriers between the bosses are widened as indicated at 26in Fig. 1, this widened portion ex- .tending between the bosses on eachside of each carrier and preventing any material displacementlongitudinally of the carriers. It is to be understood that thesecarriers are slightly less in width than the respective slot 22 providedtherefor in the bosses to allow for expansion due to heat developed inoperation and the widened side walls 26 are slightly less in length thanthe distance between a pair of bosses 13 and 14, the purpose being toprovide for freedom of action of the carrier and prevent binding thereofdue control element including the cones l7 and 18 longitudinally ineither direction in the aperture 2 of the body, one set of pins 15, asfor instance those in thebosses 14, will be moved outwardly while thoselocated in the bosses 13 will be moved inwardly or vice versa dependingupon the direction of movement of the control element. By suchlongitudinal movement of the control element, therefore, the .faces ofthe abrasive members will be positioned at an angle to the longitudinalaxis of the tool and therefore the base or bottom surface of the carriercontacting the respective pin 15 is provided with a rounded portion 2'7which extends transversely of the carrier and contacts the pin on adiametrical line passing through its axis. Thus, any movement of thecone adjusting members from a neutral position causes these roundedportions 27 to rock on the outer pin ends. It is also to be noted thatthe rounded portion 2'7 merges into grooves 28, 28 on opposite sidesthereof which will permit considerable movement of the pins outwardlywithout the edge of the pins engaging the bottom of the carrier member.Thus the action of the cones in their movement hereinafter described isnot magnified or distorted through contact of the edge of the pins withthe carrier, the point of contact between the carrier and pins beingmaintained practically on a diametrical line of the pin at all times.

Instead of the carrier 20 being provided with the rounded portions 27engaged in the outer ends of the pins to provide a ball like contactbetween the pins and the carrier, the pins themselves may have a roundedor ball like outer end indicated at 29 in Fig. 5 and as is also shown inthe said figure the inner ends of the pins may be provided with a ballend 30 of comparatively short radius so that the contact of the pin withthe respective cones and with the bases of the carriers is a pointcontact. By the means described and shown in either Figs. 3 or 5 thereis the maximum of freedom provided in the relative movement of the partsin the grinding operation as will be understood more fully from thedotted position of the abrasive in Fig. 5. In this figure the floatingcontrol member, including the cones 17a and 18a and connecting rod 12a,has moved longitudinally causing the lower end of the abrasive membersto be contracted and the upper end thereof expanded to a like degree andthis relationship of the stones at an angle to the axis of the tool mayarise upon the setting of the tool in a cylinder having a tapered walland thus the faces of the abrasives are set into positive contact withthe wall under pressure at an angle to the axis of the tool. As the toolis reciprocated in this type of aperture the stones will rocklongitudinally through the shifting of the control member due to thevarying pressure imposed thereon by the abrasives through the pins 15adjacent each end, it being readily understood that as pressure isreleased at either one end or the other of the abrasives, depending uponthe character or form of the wall being ground, the excess pressure uponone of the cones will cause the control unit to be moved to equalize thepressure on the two cones. Thus the stone faces, by reason of thiscontrol element providing a positive backing for the abrasives, willconform to the wall being ground and as the tool is reciprocated andpressure hecomes equalized at opposite ends of the stone through thecutting operation the stones assume a position parallel with the toolaxis as the stones grind themselves free. At this time the adjustingmembers areagain set up by means ofthe adjusting screw 12 or 12a and theoperation repeated. It will thusbe seen that the tool grinds by reasonof the positive pressure with which the stone faces engage the wall anddue to the freedom of movement of the parts, as heretofore described,- ahigher pressure may be imposed upon these stones .than was possible inthe tool as shown in my Patent No. 1,610,681 above mentioned in that theexpansion of the parts through heating does not cause a binding of theparts or a lessened freedom of the rocking motion occasioned in thereciprocation of the tool in a cylinder whose walls are out of round orare tapered.

In Figs. 3 and 5 I have shown by full lines the position of the stoneswhen the control element is" in neutral position and by dotted lines inFig. 5 the position assumed by the stones in engaging a wall whose faceis at an angle to the longitudinal axis of the tool and it is thispossible movement of the abrasive that I' have termed a rocking 1movement. In Fig. 4, the abrasive holders and carriers 20 are shown asbeing formed of sheet in the .grinding operation. Also, in this holderand even in the form of carrier shown in Fig. 4, the stones may besecured in place in any approved manner not only by the use of a solder,as is suggested in Fig. 4, but by means of a shellac or other screwdriver to turn the bolt 12 or 12a as the case may be. It is to beunderstood, however, that a rod indicated by dotted lines 32 in Fig. 5,may be secured in any approved manner to the bolt 12 or 12a andextending outwardly through the hollow driving member 6 or 60. of Figs.3 and 5 to permit an adjustment of the distance apart of the -conemembers in either case without disassembling the driver from the drivingrelationship with the collar 5 and end 3 or 3a of the body in the twoforms of the structure shown. In view of the fact that the drivingmember is pivotally connected with the end of the body it is preferablethat such adjusting rod 32 ispivotally connected with the head 11 or110. of the adjusting screw 12 or 12a. Such pivotal arrangement issuggested in Fig. 5 by dotted lines, the end of the rod 32 beingunderstood as entering a recess in the head of the adjusting screw andapin indicated at 33 is secured therein passing through the end of therod 32. In the form of the carrier shown in Figs. 5 and 6 the garterretaining springs 34 are carried by pins 35 secured in the ends of thecarrier 31, each of these pins being provided with a circumferentialgroove in which the springs seat.

From the foregoing description it will become evident that the structureshown by the drawings is one in which there is great freedom of actionof the parts provided for. Preferably also these cone members are formedwith cylindrical end portions 40 finished to be a sliding fit in thefinished bore 2.0f the body. Thus. these cylindrical portions take thestrain imposed thereon by the pins and the abrasive members inoperation. As this strain is unequal in a grinding operation in acylinder that is out of round or tapered even though an even number ofstones are provided, as shown, the said cylindrical portions preventlateral displacement of the cones. Thecones are thus held with theiraxes coinciding with the longitudinal axis of the tool at all times andthus the faces of the abrasives are held to a true circumferential linewhile in operation. Therefore by the construction set forth the tool isadapted to grind a cylinder to practically true round condition and astraight wall from end to end parallel with the axis of the tool andaperture.

Having thus fully described my invention, its mode of operation andrelationship of the parts by which the various objects thereof aresecured, what .I claim and desire to secure by Letters Patent of theUnited States is 1. In a tool for grinding cylindrical apertures, ahead, a series of abrasive holders carried by the head and radiallyadjustable therein, said head having a central longitudinal aperture, anadjustable control element therein for adjusting the abrasive holdersradially and providing a positive backing or support for the abrasiveholders, said control element being movable in its adjusted relation inthe body whereby variation in pressure between opposite ends of theabrasive holders may move the control element to cause the abrasiveholders to be moved outwardly at that end subjected to the leastpressure and inwardly at the opposite end, and means integral with thebody directly engaging the abrasive holders for holding the abrasiveholders from lateral displacement in the grinding operation.

2. In a grinding tool for operation on members having cylindricalapertures, the combination of a head having a hollow interior, a seriesof abrasive members extending longitudinally of the head, a controlelement mounted to move longitudinally of the hollow interior of' thehead, pins extending radially of the head to engagement with theabrasive members at the outer end and with the control element at theimier end, there being a pin adjacent each end of each abrasive member,said control element including a pair of oppositely disposed conemembers with which the inner ends of the pins engage respectively, saidpins being unattached to either the abrasive member or the said conewhereby movement of the control element in one direction or the other ofthe head causes the pins at one end oi th'e abrasive members to beextended and at the other end to be moved inwardly under pressuresexerted upon the face of the abrasives in the grinding operation, andmeans preventing displacement of the stones circumferentially of thehead.

3. In a tool of the character described, a body,

.a series of abrasive elements extending longitudinally of the body, acontrol means by which the distance of the faces of the abrasiveelements from the axis of the tool may be varied, the body of the toolbeing formed to provide a channel to receive the abrasive elementswhereby the same are held from lateral displacement circumferentially ofthe tool, means whereby the pressure to which the abrasive element issubjected in the grinding operation tending to contract the abrasiveelements is transmitted to the control means, the said control meansbeing of a character to be moved by the said pressure to substantiallyequalize the same at opposite ends of the abrasive members, the saidabrasive elements being free to assume a position at an angle to theaxis of rotation of the tool.

4. A tool for grinding cylindrical apertures comprising a head, aplurality of abrading members extending longitudinally of the head andradially adjustable therein, a control element for adjusting the radialposition of the abrasive members, spring members tending to contract theabrasive elements and the control element fixing the general limit ofcontraction, means interposed between the abrasive elements and thecontrol element and unconnected with either by means of which thepressure imposed on the abrasive elements in operation is transmitted tothe control element, the said control element being free to be movedlongitudinally of the head by reason of excess pressure at one end orthe other of the abrasive elements.

5. A tool for grinding cylindrical apertures comprising a head having acentral longitudi nal aperture, two series of radial apertures arrangedcircumferentially of the body in spaced relation longitudinally thereofand opening into the central aperture, a pair of cones inadjustablyrigid relation in the central aperture, a pin freely slidable in each ofthe radial apertures,

one series of pins having the inner ends contacting one of the conemembers and the other series contacting the other member, a series ofabrasive elements equal in number to the number of pins of one serieslying with a pin of each series in contact therewith adjacent therespective ends 4 of the abrasive member, means on the head forsupporting the abrasive members from lateral 6. A tool for grindingcylindrical apertures comprising a head having a central longitudinalaperture, two series of radial apertures arranged circumferentially ofthe body in spaced relation longitudinally thereof and opening into thecentral aperture, a pair of cones having the small ends in spacedrelationship slidable in the bore, means for varying the distance apartof the cone members, a pin freely slidable in each of the radialapertures, the pins of one series of apertures having the inner endsthereof engaging one of the cone members and the pins of the otherseries engaging the other cone, a series of 'abrasive elements extendinglongitudinally of the tool even in number to the number of the pins ofone series and arranged with a pin of each series engaging loosely; withthe respective abrasive member, spring means tending to hold theabrasive members in contact with their respective pins, and means forpreventing longitudinal and lateral displacement of the abrasivemembers.

'7. A tool for grinding cylindrical apertures,

comprising a head having a central longitudinal aperture and two seriesof radial apertures opening thereinto and in spaced relationlongitudinally of the head, a series or" bosses for each of the saidseries of apertures, pins in the said apertures and bosses, the saidbosses each having a channel parallel with the axis of the head intowhich the outer end of the pin extends in each instance, an abrasiveelement consisting of a metal holder and an abrasive stone securedtherein lying in aligned channels and in contact with the pins extendingthereinto, a control element in the longitudinal aperture of the headconsisting of a pair of cone members in opposed adjustable relation, theinner ends of the pins of each series engaging the respective cone, theopposite ends of the pins being rounded for contact respectively withthe cone and the holder of the abrasive element, spring means foryieldably holding the abrasives in the channels in contact with thepins, the control element being supported longitudinally of its aperturesolely by reason of engagement of the pins therewith.

8. In a tool for grinding cylindrical apertures, a head, a series ofabrasive members extending longitudinally thereof, said head havingchannels in which the abrasive members are loosely mounted, anadjustable control element, means interposed between the control elementand each abrasive member and unattached to either thereof whereby theadjustment of the control element varies the radial distance of thefaces of the abrasives from the axis or" the tool, the said abrasivemembers lying in engagement with the respective interposed means, andspring means for holding the abrasives in the respective channels and incontact with the respective interposed means.

9. In a tool for grinding cylindrical apertures, a head having alongitudinal aperture and two series of radial apertures openingthereinto, a

control element consisting of a pair of cones in opposed spaced relationfreely movable in the 10. In a grinding device, a head having alongitudinal bore, a series of abrading members carried by the headradially adjustable relative thereto, a control element in the said borearranged for adjustment of the abrading members, and spaced elementsinterposed between each abrading member and the control element,unattached to either thereof, and through the medium of which anadjustment of the control element varies the position of the abradingmembers relative to the axis of the tool.

11. In a grinding device, a head having a longitudinal bore, a series ofabrading members carried by the head and radially adjustablerelativethereto, a control element in the said bore ior adjusting theabrading members, said control element being movable longitudinally ofthe body in either direction, and spaced elements interposed betweeneach abrading member and the control element unattached to eitherthereof and together with the control element positively limiting theextent of contraction of the abrading members.

12. In a lapping tool, a shank, a tubular frame mounted upon said shankhaving a series of circumferentially spaced apertures therein, a cammember slidably mounted within said frame, a plurality of stone holderspositioned upon said frame, and members slidably mounted in theapertures aforesaid and engageable with the stone holders and cammember.

13. In a lapping tool, a shank, a tubular frame positioned upon saidshank having a series of spaced apertures therein, a cam member alsopositioned within the tubular frame, pins slidably mounted within saidapertiu'es and engageable with said cam member and unattached thereto, aplurality of stone holders pivotally mounted upon said frame and havingportions extending through the apertures aforesaid rockably engag ingsaid pins and unattached to them, and means for positively moving saidcam longitudinally of the tubular frame for adjusting the stone holdersradially.

14. A grinding device comprising a body, a plurality of abrasivecarriers movable laterally on said body, an expanding device movablymounted on said body, and intermediate shifting members floating on saidbody and engaging with said expanding device and said abrasive carriersand unattached to either of them. I

15. In a lapping tool, a body provided with radial recesses in the outersurface thereof,

lapping members arranged in said recesses, and

means for adjustably and rockably supporting said lapping membersincluding radially adjustable pin members projecting into said recessesandengaging said lapping members and unattached to them.

16. In a lapping tool, a body provided with radial recesses in the outersurface thereof, lapping members arranged in said recesses, and meansfor rockably suppor.ing and radially adjusting said lapping membersincluding radially adjustable pin members projecting into the bottom ofsaid recesses and engaging the lapping members intermediate their endsand unattached to them.

17. In a lapping tool, a body formed with a longitudinal bore and radialapertures, radially adjustable hone guiding members carried by saidbody, adjustable blocks in said bore, and pin members in said aperturesengaging said guiding members intermediate the ends of said members andunattached to them, said pin members being Ill radially adjustable uponmovement of said blocks.

18. In a lapping tool, a body formed with radial rece'sses and a bore, apair of blocks in said bore, means for adjusting said blocks, honeguiding members in said recesses, and means for permitting alongiudinally rockable movement of said guiding members in said recessesincluding pin members supporting and unattached to said guiding membersand slidable radially in said body by means of said blocks.

19. In a lapping tool, a body provided with a central longitudinal boreand radial recesses in the outer surface thereof, hone guiding membersarranged in said recesses, radially adjustable pin members projectinginto the bottom of said recesses for supporting said guiding members andunattached to them, and adjustable blocks in said bore engaging inclinedsurfaces on said pin mem bers for radially adjusting the same.

20. In a lapping tool, a body provided with a central longitudinal bore,radial recesses in the outer face thereof and radial aperturesconnecting said bore to said recesses, a threaded shaft in said bore,adjustable blocks on said shaft, pin members arranged in said aperturesand provided with inclined surfaces engaging said blocks, said pinmembers extending into said recesses, and hone guiding members insaid'recesses supported by and unattached to said pin members.

21. In a lapping tool, a body provided with a longitudinal bore andradial apertures communicating therewith, adjustable blocks within saidbore, radially adjustable pins arranged in said apertures provided withinclined surfaces engaging said blocks, and hone guiding membersslidably secured to said body in engagement with and unattached to saidpins.

22. In a lapping tool, a body provided with a central longitudinal bore,hone guiding members arranged in recesses in the outer face of saidbody, radial apertures extending from said bore to said recesses,adjusable blocks arranged in said bore, and pin members arranged in saidapertures engaging said blocks and projecting into said recesses forsupporting said guiding members and unattached to them.

23. In a lapping tool, a body formed with a central longitudinal bore,recesses in the outer surface and radial apertures communicating withsaid recesses and bore, adjustable blocks in said bore, pin members insaid apertures engaging said blocks and hone guiding members arranged insaid recesses and engaging said pins intermediate the ends of saidguiding members and unattached to them whereby a radial and rockableadjustment of said guiding members is permitted.

24. A grinding device comprising a body, a plurality of abrasive membersmovable laterally on said body, an expanding and contracting devicemounted on said body, and intermediate shifting members guided on saidbody and engaging with said expanding and contracting device and saidabrasive members and unattached to either of them.

25. A grinding device comprising a body, a plurality of abrasive membersmovable laterally on said body, an expanding andcontracting devicemounted on said body, andintermediate shifting members guided on saidbody and engaging with said expanding and contracting device and saidabrasive members and unattached to either of them and said abrasivemembers rockably engaging said shifting members.

26. A grinding device comprising a body, a plurality of abrasive membersmovable laterally on said body, an expanding and contracting devicemounted on said body, and intermediate sets of longitudinally spacedshifting pins guided on said body and engaging with said expanding andcontracting device and said abrasive members and unattached to either ofthem.

27. A grinding device comprising a body, a plurality of abrasive membersmovable laterally on said body, an expanding and contracting devicemounted on said body, and shifting pins guided on said body and engagingwith said expanding and. contracting device and said abrasive membersand una tached to either of them.

23. In a grinding device, a head having a longitudinal aperture andaligned radial apertures opening thereinto, a control element comprisinga pair of cam members in opposed spaced relation freely movably in saidlongitudinal aperture, pins slidable in said radial apertures, the innerends of said pins engaging the respective cam members and an abrasiveelement the outer ends of which lie loosely in contact with said alignedpins.

29. In a .grinding device, a head having a longitudinal aperture andaligned radial aper- I a control element in said bore arranged for jadjustment of said abrading member, and spaced elements interposedbetween and unattached to said abrading member and said control element,and through the medium of which spaced elements an adjustment of saidcontrol element;

varies the position of said abrading member relative to the axis of thetool.

31. In a lapping tool, a shank, a tubular frame positioned upon saidshank having spaced apertures therein, a cam member positioned withinsaid tubular frame, pins slidably mounted within said apertures andengageable with said cam member and unattached thereto, a stone holdermounted upon said frame and having portions extending through saidapertures rockably en- 1 gaging said pins and unattached to them, andmeans for positively moving said cam longitudinally of said frame foradjusting said stone holder radially.

32. In a lapping tool, a body provided with a radial recess in its outersurface, a lapping member in said recess, and means'for adjustably androckably supporting said lapping member including radially adjustablepin members projecting into said recess, engaging said lapping memberand unattached thereto.

33. In a lapping tool, a body formed with a longitudinal bore and radialapertures, a radially adjustable hone supporting member carried by saidbody, adjustable control members in said: bore, and pin members in saidapertures engaging said hone supporting member intermediate its ends,said pin members being radially adjustable upon movement of said controlmembers and unattached to them.

34. In a grinding device, a'head having a 1ongitudinal bore, a series ofabrading members extending longitudinally of the head incircumferentially spaced relation and radially adjustable relativethereto, a control element in the said bore including a pair ofoppositely disposed cones movable longitudinally of the bore in eitherdirection as a unit, means interposed between each abrading element andthe control element, said interposed means engaging the respective coneson the .one side and engaging the respective abrading element adjacentits opposite ends and being unattached to either the control element orthe abrading element, the said interposed means providing a means fortransmitting pressure to which the abrading elements are subjected inthe grinding operation to the control element and in variable degree tothe respective cones as the pressure on the opposite ends of theabrading element varies.

35. In a lapping tool, a body provided with a. central longitudinalbore, hone guiding members arranged in recesses in the outer face ofsaid body, radial apertures extending from said bore to said recesses,adjustable blocks arranged in said bore and intermediate shiftingmembers arranged in said apertures engaging said blocks and projectinginto said recesses for supporting said guiding members.

36. In a lapping tool, a shank, a tubular frame.

38. A grinding device comprising a body, an abrasive member movable onsaid body, an expanding device mounted on said body, and intermediateshifting means engaging with said expanding device and said abrasivemember and unattached to either of them.

39. A grinding device comprising a body, an abrasive member movablelaterally on said body,

.an expanding and contracting device mounted on said body, andintermediate shifting means guided on said body and engaging with saidexpanding and contracting device and said abrasive member and unattachedto either of them.

40. A grinding device comprising a body, an abrasive member movable onsaid body, an expanding device mounted on said body, intermediateshifting means engaging with said expanding device and said abrasivemember and unattached to either of them, and said abrasive memberrockably engaging said shifting means.

41. A grinding device comprising a body, an abrasive member movable onsaid body, an expanding device mounted on said body, intermediateshifting means engaging with said expanding device and said abrasivemember and unattached to either of them, and spring means for holdingthe abrasive in contact with said intermediate means.

42. A grinding device comprising a body, an abrasive carrier movablelaterally on said body, an expanding device movably mounted on saidbody, and intermediate shifting means floating on said body and engagingwith said expanding device andsaid abrasive carrier and unattached toeither of them.

43. In a lapping tool, a shank, a tubular frame mounted upon said shankand having an aperture therein, a cam member slidably mounted withinsaid frame, a stone holder positioned upon said frame, and meansslidably mounted in said aperture and engageable with said stone holderand said cam member.

MARSDEN c. HUTTO.

